Backpack with removable wheels

ABSTRACT

Rollers are fastened to a chassis which is removably held to a bottom of a backpack by hook and loop fasteners. The rollers are on legs which are rotatably mounted at one end so the rollers can be moved from a first, compact position to a second, expanded position to provide better stability to the backpack which rests on the rollers. Another hook and loop area on the backpack can be used to store the rollers and chassis when they are removed from the bottom of the backpack.

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of provisional patentapplication No. 60/437,634 filed Jan. 31, 2002, the complete contents ofwhich are incorporated herein by reference.

BACKGROUND OF THE INVENTION

[0002] This invention relates to a method and apparatus for selectivelyproviding a backpack with wheels to facilitate movement of the backpackwhile removing the wheels when the wheels are not in use.

[0003] Students often use backpacks to carry school supplies and books.The backpacks often become very heavy, especially when many books arecarried home or carrued between classes. Heavy backpacks can harm thestudents, especially by weakening or injuring the backs of the studentscarrying the heavy backpacks. Putting wheels on the backpacks allows thebackpacks to be pulled, and reduces the amount of weight that must becarried. But the wheels present problems when the backpacks are put on aperson's back, as the wheels may collect debris from the ground and thedebris rub off on the student's backs when the backpacks are worn, orthe wheels hit other students causing injury or transferring debris.There is thus a need for a backpack which can be pulled on wheels, +butwhich avoids the disadvantages of having exposed wheels when thebackpack is worn on a person's back.

[0004] In some circumstances there may also be a social stigma ordisincentive for using wheels on backpacks. Some people just don't wantto be seen pulling a backpack on rollers or seen having a backpack withrollers. There is thus a need for a backpack with wheels that can beeasily and quickly removed from the backpack.

SUMMARY OF THE INVENTION

[0005] One or more rollers are removably fastened to a backpack by useof hook and loop fasteners on the backpack and on a roller assembly.Advantageously there are four rollers fastened to a chassis, with therollers being mounted to movable support legs which allow the rollers toseparate and provide a larger and more stable support. The chassis issufficiently large to provide enough area for the hook and loopfasteners to keep the rollers and chassis fastened to the backpackduring use. A separate patch of hook or loop material can be fastened tothe backpack to allow the rollers to be removed from the bottom of thebackpack, and placed on the patch to be held in a storage or non-uselocation.

[0006] One embodiment of the invention thus comprises a wheeled backpack having at least one roller and means for removably fastening the atleast one roller to the backpack. Advantageously the backpack has one ofa hook or loop fastener on an exterior of a bottom of the back pack. Amounting chassis has the other of a hook or loop fastener fastened tothe chassis so the chassis can be removably connected to the backpack.At least one roller is mounted to the chassis and preferably there are aplurality of rollers connected to the chassis.

[0007] Moreover, it is preferable that each roller is connected to asupport which is mounted to and rotates relative to the chassis to allowthe support to change position relative to the chassis. In a preferredembodiment there are four rollers each connected to a separate support.The support advantageously has a first end rotatably fastened to thechassis to rotate in a plane to allow positioning of the wheels relativeto each other parallel to that plane.

[0008] In a further variation, the backpack has the one of the hook orloop fasteners at two locations, one location for holding the rollersduring use, and one location for holding the rollers during non-use,with each of the fasteners being of sufficient size to hold the chassisto the backpack. In still further variations, the backpack has twoshoulder straps for carrying the backpack and the chassis is removablyfastened by the hook and loop fasteners to either a side or a bottom ofthe backpack.

[0009] This invention also includes a method of fastening wheels to abackpack, including placing one of a hook or loop fastener on a backpackat a first location on an exterior side, bottom or back of the backpack.The method further includes placing the other of a hook or loop fasteneron a chassis. At least one roller is fastened to the chassis, with thehook and loop fasteners being of sufficient size to hold the chassis tothe back pack when the backpack rests on the wheels and is rolled on afloor during use of the backpack.

[0010] In a further embodiment the method includes fastening each rollerto a support that is movably relative to the chassis so the rollers canbe positioned relative to each other. Advantageously, but optionally,the method includes fastening a mating hook or loop material to thebackpack at a second location on a side, front or back of the backpack.Further, a pulling strap can also be fastened to the backpack. In themost preferred embodiment, the method includes fastening two shoulderstraps to the backpack and located so a person's arms can fit throughthe straps and carry the backpack on a back of the person.

[0011] These and other advantages of the invention will become moreapparent in connection with the following drawings in which like numbersrefer to like or corresponding parts throughout the description.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012]FIG. 1 is a perspective view of a roller assembly and strap foruse with a backpack;

[0013]FIG. 2 is a perspective view of the bottom of the roller assemblyof FIG. 1 in a retracted position;

[0014]FIG. 3 is a perspective view of the bottom of. the roller assemblyof FIG. 1 in an expanded position;

[0015]FIG. 4 is an exploded perspective view of a roller assembly andfastening mechanism as partially shown in FIG. 1;

[0016]FIG. 5 is a perspective view of the bottom of the roller assemblyof FIG. 1 before being fastened to a backpack;

[0017]FIG. 6 is a perspective view of the bottom of the roller assemblyof FIG. 1 after being fastened to a backpack;

[0018]FIG. 7 is another perspective view of the backpack of FIG. 6;

[0019]FIG. 8 is a perspective view of the backpack of FIGS. 5-7 with theroller assembly stored on the backpack; and

[0020]FIG. 8 is a perspective view of the bottom of the roller assemblyof FIG. 1 fastened to a container.

DETAILED DESCRIPTION OF THE INVENTION

[0021] Referring to FIGS. 1, 5 and 6, a roller assembly 10 is providedwhich is removably fastened to a backpack 12 by hook or loop fasteners14 having hooked portion14 a and loop portion 14 b. The roller assembly10 has one or more rollers 16 with the illustrated embodiment havingfour rollers to provide a more stable support for the backpack 12.Advantageously, but optionally, each roller is mounted to a frame orchassis 18 rather than being separately mounted to the backpack, withthe chassis 18 having one of the hook or loop fasteners 14 a, 14 b sothe chassis can be mounted to the backpack 12 which contains the otherof the hook or loop fasteners 14 a, 14 b. Further, the rollers 16 arepreferably, but optionally mounted to supports 20 which are fastened tothe chassis 18 and movable relative to the chassis so the rollers 16 canbe spread apart to provide a wider support for the backpack 12. Apulling strap 22, preferably a removable strap, is fastened to thebackpack 12 to allow the backpack to be pulled over the ground or othersurfaces during use. When the backpack is not in use, the hook and loopfastener 14 allows removal of the roller assembly 10, which may then bestored inside the backpack, or alternatively fastened to a storage hookor loop area 24 which is located on the outside or inside of thebackpack, or located elsewhere, as in a locker of the user.

[0022] Referring to FIGS. 1-4, the roller assembly 10 is further shown.In its simplest form the roller assembly 10 includes a roller 16 havinga surface suitable for fastening to the hook and loop material 14.Referring especially to FIG. 4, the rollers 16 advantageously comprisecommercially available casters which rotate about at least a first axis26 which is typically parallel to the ground during use of the rollerassembly. The rollers 16 preferably also advantageously also rotateabout a second axis 28 which is orthogonal to the first axis 26, andwhich is typically vertical during use of the roller assembly 10. Thecasters 16 typically have a mounting plate 30 which accommodates abushing or bearing and allows rotation about the second axis 28. In itssimplest form the roller assembly fastens one of the hook or loopportions 14 a, 14 b to the mounting plate 30 for fastening to thebackpack 12.

[0023] Preferably though, there are a plurality of rollers 16 each ofwhich is fastened to the chassis 18. The mounting plates 30 of eachroller 16 may be fastened directly to the chassis 18 by passing threadedfasteners through holes 32 in the mounting plate or otherwise securingthe mounting plate to the chassis using various known fasteningmechanisms including adhesives, welding, sewing, and other known means.But advantageously the rollers 16 are each mounted to a support 20 whichis in turn fastened to chassis 18.

[0024] The supports 20 are shown as comprising flat, elongated metalplates with a roller 16 fastened to a distal end of the plate, and withthe opposing end movably fastened to the chassis 18, which is alsopreferably a metal plate. Edges of each plate can be rolled to formstiffening ribs to strengthen the supports 20 or chassis 18. Otherstiffening mechanisms can be used, such as internally located ribs.Because of the elongated nature the supports 20 will be referred to assupport legs 20, but various shapes could be used. Passing an impactrivet 33 through a hole 34 a (FIG. 4) in the movable end of the supportleg 20 and a mating hole 34 b in chassis 18, and forming an enlargedhead on opposing ends of the rivet, allows the support leg to be rotablyfastened to the chassis 18. Bearing assemblies, pin and clevisarrangements and other rotatable connections could be used, but the arivet loose enough to allow rotation allows a low profile, inexpensiveconnection that is believed to be sufficiently durable for the intendeduse on a backpack with shoulder-carrying straps.

[0025] Advantageously each support leg 20 has a detent mechanism to holdthe support legs 20 in a desired orientation relative to the chassis 18.One way to form the detent mechanism is to have one or more projections36 or one or more recesses 38 which removably receive a matingprojection 36 or recess 38 on the adjacent side of the chassis 18. Therecess 38 could be on either, or both of the support leg 20 and chassis18, with the mating projection 36 located on the other of the supportleg 20 and chassis 18. Other types of detent mechanisms could be used,and other position retention mechanisms could be used, includingfrictional position mechanisms.

[0026] Still referring to FIG. 4, a clamp plate 40 is adjustably urgedagainst one or more of the rotatable ends of the support legs 20 to holdthe legs 20 in a desired position. This can be achieved several ways,but the illustrated embodiment uses a threaded post 42 extending fromthe chassis 18. Advantageously, but optionally, the threaded post 42 isformed by a flat headed screw which extends through a countersunk holein the chassis 18 and through a corresponding hole in clamp plate 40. Anut or preferably a manually grippable knob 44 fastens onto the distalend of the post 42. By tightening the knob 44 the clamp plate 40 canforce a portion of the support legs 20 against the chassis and restrainmovement of the legs 20. Other clamping mechanisms known to thoseskilled in the art could be used given the present disclosure.

[0027] Referring to FIGS. 2-4, the projections and recesses 36, 38 arelocated on a longitudinal axis of each support leg 20, but they could belocated elsewhere. In the depicted location, the projections andrecesses 36, 38 engage to maintain the support legs 20 along twoparallel lines, and keep the rollers 16 in pairs in which two rollersare adjacent each other. This provides a compact storage configuration.The rotatable connection of the support legs 20 to the chassis 18 allowsthe support legs to rotate so the rollers 16 move away from each otherinto an expanded position as shown in FIG. 3. The rollers 16 and supportlegs 20 can be maintained in this expanded position by providing adetent mechanism as previously described. But preferably the knob 44 istightened to releasably clamp the legs 20 into position. In the expandedposition the support legs 20 are advantageously aligned along twointersecting lines, generally forming a cross or X.

[0028] One or more of the detent mechanism, the tightening knob and theother releasable fastening mechanisms thus provide means for releasablyfastening the support legs 20 in position, either in the storageposition, or in the expanded position which is believed preferable foruse of the roller assembly, as described later.

[0029] Referring to FIGS. 4 and 5, the side of the chassis 18 oppositethe rollers 16 has a surface to which is fastened one of a hook or loopfastener 14 a, 14 b. For illustration a hook material 14 a is shown, butit could be the loop material 14 b. Adhesives can fasten the hookmaterial 14 a to the chassis. A hook material with a self-adhesivebacking is believed suitable. Advantageously the hook material 14 a hasholes cut through it so that various fasteners, such as rivets 33 canpass through and do not impede the use of the hook material adjacent thefasteners and holes. A corresponding amount of loop material 14 b isfastened to the backpack 12. Preferably the loop material 14 b isfastened by adhesives, but it could be fastened by other knownmechanisms, such as sewing, rivets, etc. In use, hook and loop materials14 a, 14 b abut and engage in order to releasably fasten the rollerassembly 10 to the backpack 12.

[0030] The strap 22 is fastened to the backpack 12 and used to pull thebackpack so it rolls along the ground or other surface on rollers 16.Depending on the size and shape of the backpack, and the contents of thebackpack, the size of the roller assembly may vary. In the compactconfiguration shown in FIG. 5, the rollers 16 are aligned in a narrowrectangle with the four rollers in two pairs, and the rollers in eachpair being next to each other. That configuration will work for lightloads and smaller backpacks when the backpack towed along the ground.For larger or heavier backpacks 12, the rollers 16 may be spread apartand held in place by the detent mechanism. Preferably though the clampplate 40 and knob 44 are used as shown in FIG. 6. The knob 44 isloosened to move the rollers 16 into a spread apart position, and thenthe knob is tightened to hold the rollers in position. The spread apartrollers 16 provide a wider base and a more stable rolling support forthe backpack 12. The spread.apart rollers 16 are also useful on thosebackpacks 12 which have a flexible bottom. Advantageously, the backpack12 has a stiffener in the bottom of the backpack, such as a piece ofplastic or cardboard as are typically used. That helps prevent the edgesof the backpack 12 from hanging over the rollers 16 and rubbing on theground. The spread apart configuration of FIG. 6 helps distribute theweight on the bottom of the backpack over the chassis and support legs20, and provides a better and more stable support for the backpack.

[0031] Referring to FIGS. 7-8, when the roller assembly 10 is not in useor not being used to roll the backpack on the ground, the assembly 10may be removed at the option of the user. Preferably, but optionally, astorage patch 46 of hook or loop material is placed on the backpack 12so the roller assembly 10 may be held by the storage patch of material.Whether the patch 46 is formed of a hook material 14 a or loop material14 b depends on what material is fastened to the chassis 18, as thepatch 46 must be the opposite so it will cooperate to form a hook andloop connection. The storage patch 46 is shown located on one side ofthe backpack 12, but it could be on the top, or the front of thebackpack, or it could be on the inside of the backpack. The rollerassembly 10 could also be simply placed inside the backpack, or in apocket on the backpack 12, with or without a storage patch 46 of hookand loop material to hold the roller assembly 10 in position. Similarly,a storage patch 46 could be fastened to the inside of a school locker ora user's closet or wall in order to store the roller assembly 10 whennot in use.

[0032] The roller assembly 10 can be made of various materials. A 16gauge galvanized plate is believed suitable for the support legs 20,especially with rolled edges on the plate to form stiffeners. Legs 20formed of molded polymer are also believed suitable. Various shapes ofsupports 20 and chassis 18 can be used, but the flat plates allow a lowprofile for the roller assembly and that keeps the center of gravity ofthe rollers and backpack closer to the ground, and thus provides a morestable assembly.

[0033] The roller assembly 10 can be used with ordinary, commerciallyavailable backpacks 12 which are not specifically designed for use withthe roller assembly. Advantageously the backpacks 12 have a stiffenedbottom, with a stiffening plate (not shown) in the bottom of thebackpack so the edges of the backpack do not sag over the rollers 16 andrub on the ground. But such stiffening plates are not required. As usedhere, the backpack 12 is preferably of the type that has at least oneflexible side with two shoulder straps 48 fastened to the backpack so auser can place a strap over each of the user's arm to carry the backpackon the back of the user. But the use of the roller assembly 10 is notlimited to this type of container, and the term “backpack” is to beconstrued broadly to include any type of container, especiallycontainers having one or more flexible sides, unless specificallydescribed otherwise. The use of backpacks with arm straps 48 isadvantageous, because the arm straps can be grabbed to pull the backpack12 on the roller assembly 10 so the separate pulling strap 22 is notneeded.

[0034] Alternatively, the pulling strap 22 can encircle one or both ofthe arm straps 48 to allow the user to pull the backpack 12 on theroller assembly 10. The pulling strap 22 advantageously, but optionallyhas hook and loop material along a length of the strap adjacent the endfastened to the backpack, in order to allow flexibility in fastening thepulling strap 22 to the backpack 12. The pulling strap 22 can fasten toa mating piece of hook and loop material, or it can encircle a D ringfastened to the backpack 12, or it can fasten to other suitable portionsof the backpack by means known to one skilled in the art.

[0035] The roller assembly 10 can be releasably fastened to the backpack12 by using releasable attachments other than hook and loop fasteners14. Snap-lock fasteners could be used but are not as desirable as theyare more difficult to engage and disengage. The hook and loop material14 allows easy removal and reattachment of the roller assembly and isthus preferable. The hook and loop material 14 must be large enough toprevent the roller assembly from disengaging from the backpack duringuse when the backpack is being pulled across the ground, down thesidewalk, over curbs, and during other uses of the backpack when therollers 16 are attached. An area of about 12 square inches of hook andloop material 14 is believed suitable for Nylon hook and loop fasteners.The hook and loop material 14 is advantageously made of Nylon or otherpolymer, but they could be made of metal such as aluminum or steel, inorder to allow larger forces to be transmitted. Depending on the typeand construction of the hook and loop fasteners, different areas ofmaterial may be needed for the hook and loop material 14.

[0036] Referring to FIG. 9, the roller assembly 10 can be fastened to acontainer 50 having any of a variety of shapes. The roller assembly 10in FIG. 9 can have the hook and loop material 14 mating with acorresponding material 14 on the container. But alternatively, the hookand loop material 14 can be omitted from the container 50, or the rollerassembly 10, and the roller assembly fastened to the container 50 byother mechanisms, such as strap 52. The straps 52 can go throughapertures or slots 54 (FIG. 4) on opposing sides of the chassis 18 tofasten the straps 52 directly to the chassis. Alternatively, the straps52 can go on the exterior side of the support legs 20 and chassis andurge those parts against the container 50, but that is less desirable.The pulling strap 22 can be fastened to one of the straps 52 whichfasten the container 50 to the roller assembly 10.

[0037] The invention also includes a kit, comprising the roller assembly10 with chassis 18 and rollers 16, and a suitable piece of hook and loopmaterial 14 a, 14 b to mount the roller assembly 10 to the backpack 12.In the kit, the piece 14 b of hook or loop material 14 advantageouslyhas a self adhesive on the back of the piece 14 b of hook or loopmaterial so it may be fastened to the back pack 12. Alternatively, avial of adhesive can be provided to fasten the hook or loop material 14to the backpack. If the roller assembly does not have any hook and loopmaterial on the chassis 18, then the kit advantageously includes a pieceof hook and loop material. The kit also advantageously, but optionally,includes the pulling strap 22.

[0038] As required, detailed embodiments of the present invention aredisclosed herein; however, it is to be understood that the disclosedembodiments are merely exemplary of the invention, which may be embodiedin various forms. Therefore, specific structural and functional detailsdisclosed herein are not to be interpreted as limiting, but merely as abasis for the claims and as a representative basis for teaching oneskilled in the art to variously employ the present invention invirtually any appropriately detailed structure.

[0039] The above description is given by way of example, and notlimitation. Given the above disclosure, one skilled in the art coulddevise variations that are within the scope and spirit of the invention,including various ways of forming the roller assembly of one or morerollers, and various ways of removably fastening the roller assembly tothe backpack. Further, the various features of this invention can beused alone, or in varying combinations with each other and are notintended to be limited to the specific combination described herein.Thus, the invention is not to be limited by the illustrated embodimentsbut is to be defined by the following claims when read in the broadestreasonable manner to preserve the validity of the claims.

What is claimed is:
 1. A wheeled back pack, comprising: a backpack; atleast one roller; means for removably fastening the at least one rollerto an exterior surface of a bottom the backpack.
 2. The back pack ofclaim 1, wherein the means comprise hook and loop fasteners.
 3. Awheeled backpack, comprising: a backpack having a bottom and a side,with one of a hook or loop fastener fastened to the backpack using thehook or loop fastener; a mounting chassis having the other of a hook andloop fastener fastened to the chassis so the chassis can be removablyconnected to the backpack; at least one roller mounted to the chassis.4. The backpack of claim 3, wherein the at least one of the hook andloop fastener if fastened to an exterior surface of the bottom of thebackpack.
 5. The backpack of claim 3, wherein the chassis comprises aplate with the other of the hook or loop fastener fastened to a firstside of the plate.
 6. The backpack of claim 5, wherein there are aplurality of rollers connected to the chassis.
 7. The backpack of claim3, wherein there are a plurality of rollers at least some of which areconnected to at least one support which moves relative to the chassis toallow the support to change a position of the roller connected to thatsupport.
 8. The backpack of claim 3, wherein there are four rollers eachconnected to a support having a first end rotatably fastened to thechassis.
 9. The backpack of claim 3, wherein there are four rollers eachconnected to a support having a first end rotatably fastened to thechassis to rotate in a plane to allow positioning of the wheels relativeto each other parallel to that plane.
 10. The backpack of claim 3,wherein there are four rollers each connected to a support having afirst end rotatably fastened to the chassis to rotate in a plane, therollers and supports having a first position in which the supports aresubstantially parallel and a second position in which the supports arealigned along intersecting lines.
 11. The backpack of claim 3, whereinthere are four rollers each connected to a support having a first endrotatably fastened to the chassis to rotate in a plane, the rollers andsupports having a first position in which the rollers are adjacent eachother, and a second position in which the rollers are spaced furtherapart than in the first position.
 12. The backpack of claim 3, whereinthe backpack further has the at least one of the hook or loop fastenersat two locations, and each of sufficient size at each location to holdthe chassis and rollers to the back pack.
 13. The backpack of claim 3,wherein the backpack has two shoulder straps for carrying the backpackand the chassis is removably fastened by the hook and loop fasteners toeither a side or a bottom of the backpack.
 14. A method of fasteningwheels to a backpack, comprising: placing one of a hook or loop fasteneron a backpack at a first location on a side, bottom or back of thebackpack; placing the other of a hook or loop fastener on a chassis;fastening at least one roller to the chassis, the hook and loopfasteners being of sufficient size to hold the chassis to the back packwhen the backpack rests on the rollers and is rolled during use of thebackpack.
 15. The method of claim 14, further comprising the step offastening each roller to a support movably extending from the chassis.16. The method of claim 14, further comprising fastening each roller toa support having one end movably fastened to the chassis so the rollerscan be positioned relative to each other.
 17. The method of claim 14,further comprising, fastening a patch of the other of a hook or loopfastener to the backpack at a second location on a side, front or backof the backpack, and sizing the patch to hold the chassis and rollers.18. The method of claim 14, further comprising fastening a pulling strapto the backpack.
 19. The method of claim 14, further comprisingfastening two shoulder straps to the backpack and located so a person'sarms can fit through the arm straps and carry the backpack on a back ofthe person.